1. Field of the Invention
The invention relates to secure downloading, recovery and upgrading of data.
2. Description of Related Art
Recent developments in networking include client devices, which interact with a network to contact one or more server devices, and that are disposed for displaying information from those server devices. Division of responsibility among the clients and server allows each client device to use relatively fewer resources (such as processing power or memory) and therefore to be relatively inexpensive. Client devices can be manufactured en masse at relatively smaller cost and distributed to a large number of end users.
One problem in the known art is that client devices are subject to various failures. These can include hardware failures, which can damage software used to control the client device, and software failures, which can cause the client device to operate erroneously. It would therefore be advantageous to provide a method and system for recovery from memory errors in the client device. Moreover, there may be substantial upgrades to software designed for the client device developed after the client device has been manufactured and delivered to the end user. It would therefore be advantageous to provide a method and system for delivering these software upgrades to the client device.
This problem in the known art is exacerbated by several factors. First, as the client device is relatively inexpensive and within the complete physical control of the end user, it is unknown whether the software available at the client device can be trusted. Second, the client device itself cannot necessarily trust the data it receives from the server device it is coupled to if established over an insecure network, such as the internet. Third, the client device has relatively limited resources for communicating with the server device; in particular, the client device has relatively limited resources for rapidly receiving downloaded information from server devices.
Accordingly, it would be desirable to provide an improved method and system for secure downloading, recovery, and upgrading. This advantage is achieved in an embodiment of the invention in which a client device contacts a server device using a reliable software module. The reliable software module obtains trustworthy information with which to perform software and data integrity tests, and with which to locate data for recovery or upgrade of the client device.
The invention provides an improved method and system for secure downloading, recovery, and upgrading. A client device receives information from a server device using reliable software modules stored in permanent memory in the client device. The reliable software modules perform software and data integrity tests, and locate and retrieve data for recovery or upgrade of the client device. The client device confirms the trustworthiness of the received information device by comparing digital signatures or digests for the information it receives with known digital certificates in the reliable software module or received from known trusted server devices.